Automatic cut-off.



No. 729,116. PATENTEDl MAY 26, 1903. R. P. BARNSTEAD. AUTOMATIC CUT-OFF.

APPLICATION FILED BBPT.11. 1902.

N0 MODEL.

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UNTTED STATES Patented. May 26, 1903.

PATENT OFFICE.

AUTOMATIC CUT-oFF.

SPECIFICATION forming part of Letters Patent No. 729,1 16, dated May 26,1903. Application filed September ll, 1902. Serial No. 122,979. lNomodel.)

To @ZZ whom it may concern.-

Be it known that I, ROBERT P. BARNsTnAD, a citizen of the United States,residing in Ashmont district, in the city of Boston, county of Suolk,State of Massachusetts, have invented certain new and usefulImprovements in Automatic Cut-Offs, of which the following is a full,clear, and exact description.

The object of myinvention is the construction of an improved device bymeans of which the fuel-supply to a burner will be automatically shutoff the instant the article being heated shall reach a certain speciedtemperature, and while the device has numerous applications I havespecificallyv designed it for use in connection with sterilizers, whichare exceedingly liable to become overheated and seriously injured by thecontained water boiling away. By means of my device as soon as the waterhas all been evaporated and the bottom of the sterilizer become heatedto a slight degree above 100o centigrade a drop of solder melts andreleases a lock, thereby permitting a spring-valve to close thefuel-pipe.

Referring to the drawings forming part of this specification, Figure 1is a side sectional elevation of a sterilizer having my inventionapplied thereto. Fig. 2 is a View of the same from beneath, and Fig. 3is a sectional detail view of the spring-valve employed.

The reference numeral 1 designates the sterilizer, having a usual cover2 and my perforated tray supported on legs 8.

10 is the burner, located beneath the sterilizer and provided with gasthrough the pipe 11. The valve l2 is one which is self-closing and ofthe usual construction, as shown in Fig. 3, the only novelty in thevalve consisting of the spur or linger 14 at the extremity of thevalve-handle 13.

Beneath the sterilizer 1 and securedto its bottom a little to one sideof the burner 10 by means of a small quantity of soft solder 22 is thewire 20, having the eye 2l at its outer end. The length and location ofthis wire are such that its eye 2l just reaches the finger 14 when thehandle 13 is swung toward the left to open the valve wide. Hence allthat is necessary to do when using my device is to open the valve andslip the eye 21 into engagement with the finger 14. This retains thevalve-wide open and permits the gas to i'low uninterruptedly to theburner so long as desired. To extinguish the llame, the eye is slippedod said linger and the valve allowed to close. Should, however, thewater boil away in the sterilizer when the burner is supplied with fuel,as above described, then the instant the bottom of the receptacle risesabove its normal temperature of 100 centigrade the drop of solder 22melts, the wire 20 thereby released, and the spring-valve closed.-

The simplicity of this device is apparent, consisting, as it does, ofnothing more than a wire having an eye or hook bent up at one end; butits reliability is even more evident, inasmuch as the melting-point ofthe solder is made so low that insufficient heat to cause injury can bereceived by the sterilizer-bottom before the solder softens and releasesthe wire.

In addition to the eye 2l I prefer to lengthen the wire 2O somewhat andprovide it with a second eye 2l, proportioned to retain lthevalve-handle 13 at a point to supply only a limited quantity of fuel tothe burner, and thereby keep the latter at a low ebb, so that after thewater has been brought quicklyfto the boiling-point, with the finger 14engaging the eye 21, the valve ca-n be partly closed by the use ot' thesecond eye 2l.

What I claim as my invention, and desire to secure by Letters Patent, isas follows, to wit:

1. The combination with a burner and a .liquid-container heated thereby,of a pipe admitting fuel to said burner, a valve for said pipe having ahandle provided with a terminal extension and means for its normal self-'closure, and a Wire having one end detachably connected to said handleextension and its other en ,drsoldered to the under side of saidliquid-container, whereby said wire remains anchored so long as there isliquid in said container, but when the liquid is evaporated the soldermelts and the wire is disconnected vand the valve permitted to close.

2. The combination with a burner and a liquid-container heated thereby,of a pipe admitting fuel to said burner, a self-closing valve Vfor saidpipe having a handle formed with a terminal finger, and a wire havingone end soldered to the under side of said container and its oppositesection provided with ICO vention I have hereunto set my hand this 9th aplurality of eyes any one of which is conday of September, 1902.

structed to engage said nger and retain said valve more or less open,whereby the evapo- 1 ration of the liquid in the contain-er permitsROBER'l P BARNSTEAD 5 the Wire to be unsoldered and the valve toWitnesses:

LOWELL M. MAXHAM,

close.

In testimony that I claim the foregoing in- A. B. UPHAM.

